The Medicare payment system for SNFs has become increasingly broken, a report states.

The Medicare Payment Advisory Council needs to take a step back and conduct additional research before it votes this week on a recommendation to overhaul the post-acute payment system, according to one healthcare group.

MedPAC had previously estimated that its plan for a unified, site neutral post-acute payment system could be in place sometime after 2023. Last month the council raised the stakes, saying the system could be feasibly implemented by 2021, which would require the plan to be introduced to Congress in 2018 or 2019.

That expedited timeline may cut the amount of time the council has to collect data on the “feasibility and advisability” of speeding up implementation, the American Hospital Association said in a letter sent Wednesday to MedPAC Chairman Francis J. Crosson, M.D.

“We are concerned that such an aggressive move may reduce the reliability and accuracy of the final model, which could result in significant mis-payment and, as a result, harm access to care, particularly for high-acuity patients who use specialized post-acute services that are not provided in all of the PAC settings,” wrote AHA Executive Vice President Thomas P. Nickels.

The letter lists the steps needed to design, test and validate the unified system, including collecting data sets, running various tests, determining payment policies for outliers, and analyzing the reliability, accuracy, fairness and budget-neutrality of the model.

“It is unclear which steps would be accelerated, condensed or skipped altogether in order to achieve the timeline included in MedPAC’s draft recommendation,” Nickels wrote.

AHA called for MedPAC to work with the Centers for Medicare & Medicaid Services, as well as the Assistant Secretary for Planning and Evaluation, to determine whether the “extensive set of policy work” required by the system could be completed accurately by 2018 or 2019.

MedPAC will comment and vote on the recommendation for the unified payment system during its public meeting on Thursday.